For the purpose of accelerating the recovery of physical strength by patients during or after medical treatment, particularly by patients during or after treatment for the inhibition of nucleic acid metabolism of cancer cells, such as administration of anticancer agents and radiation, one important factor is the recovery of the hematopoietic function of bone marrow.
The hematopoietic function of cancer patients, during pharmacotherapy with anticancer agents or the like or radiotherapy, is reduced. In particular, the number of blood platelets and leucocytes in the blood of such patients is significantly reduced. This reduction in hematopoietic function necessarily leads to reduced biophylaxis. For this reason, recovery of the hematopoietic function of bone marrow is contemplated to aid in the recovery of physical strength by such patients.
Accordingly, nutritional auxotherapy in addition to surgical or chemotherapeutic treatment has been proposed for the treatment of cancer. For example, it has been considered useful to administer to patients beer yeast having a high nucleic acid content as described, for example, in Kimoto et al., Kakusan no Eiyogaku, 52, Nihon Bunshi Seigo Eiyogaku Kenkyu Zaidan (Aug. 25, 1983).
The object of the above-described therapy is to accelerate the recovery of tissue cells by patients during or after medical treatment by means of supplementing the nucleic acid synthesis ability of tissue cells through salvage synthesis (cf. page 34 of Kimoto et al.). The therapy further aims at selective utilization of the administered nucleic acids and/or the degradation products thereof, i.e., nucleotides, nucleosides and nucleic acid bases, by normal bone marrow cells, which have been partly damaged by the administration of anticancer agents and the like rather than by cancer cells by virtue of the salvage synthesis (cf. page 38 of Kimoto et. al.).
As set forth above, the administration of drugs having a high nucleic acid content in combination with pharmacotherapy or radiotherapy is considered effective in the treatment of patients with cancer.
However, when such drugs having a high nucleic acid content are given to patients suffering from hyperoxia, there is a high possibility that uric acid levels in the blood will increase, causing complications, such as gouty arthritis, tophus, renal disorders, urolithiasis, arteriosclerosis, etc.
There has been a great need, therefore, to develop a drug having a high nucleic acid content for recovering the hematopoietic function of bone marrow thereby to restore the physical strength of patients without an accompanying rise of uric acid levels in the blood that possibly causes the above-described complications.
There also has been a need to develop a nutritive source which enables patients during medical treatment as well as healthy individuals to easily recover physical strength by accelerating recovery of the function of the hematopoietic organs.